<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <style>
        #d1{
            width: 100px;
            height: 100px;
            background-color: red;
        }


    </style>

</head>
<body>


<div class="c1">div1</div>
<div class="c2">div2</div>


<div id="d1"></div>



<script src="jquery.js"></script>
<!--<script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script>-->

<script>



</script>

</body>
</html>